The joinder of sections of pipe, particularly joining a new movable section to a relatively immobile section can be required in practically any position. However, in most instances, the sections to be joined are in a horizontal position, as in building a pipeline, or in a vertical position, as in running a drill string, tubing or casing in a well. When the pipe to be joined, whether the joint be welded, screw-type or glued and whether the pipe be metallic or plastic, the alignment and holding of the pipe during joinder is a relatively simple task when the pipe diameter is relatively small. In most instances a new section of pipe is moved into place, aligned and held by hand during joining. When the section of the pipe to be joined to the relatively fixed section is too heavy or inconvenient to handle manually, a chain is generally wrapped around the movable section of pipe and a crane with a dragline is used to carry the pipe to location. However, again, the end of the movable section of pipe is guided into place and held in place for joinder by hand. More sophisticated techniques utilize tongs, jaws or clamps of some type, either manually actuated or mechanically actuated, to grip the free section of pipe and permit it to be aligned by hand for joinder. Still more sophisticated devices involve an elongated, rigid structure having a clamping means or jaws at each end thereof, manually or mechanically actuated, one of which grips the end of the relatively fixed section of pipe and the other of which grips the end of the free section of pipe. Such devices can be utilized where the pipe section is to be joined are vertically oriented or horizontally oriented and can be made more sophisticated by making the means gripping the free section of pipe movable in a longitudinal direction to bring the free section of pipe into contact with the relatively fixed section. In the use of such devices, it is assumed that since the two clamping or gripping devices are mounted on a common support structure and are longitudinally aligned, two sections of pipe clamped in such a device will necessarily have their ends aligned. While this may be true where the freely movable section of pipe is short, light and/or of small diameter, it is not necessarily the case where the pipe is extremely heavy, long and/or of relatively large diameter, particularly large diameter. All of the problems of aligning and holding pipe in place for joinder, whether of large or small diameter and irrespective of the type of pipe or the type of joinder involved, are multiplied many fold where the joinder of the pipe is carried out in offshore locations, as in the building of pipelines or the replacement or construction of exhaust stacks on floating platforms or other types of offshore structures.